Method and apparatus for minimizing pain caused by drilling teeth



April 5, 1949.

v. H. SIEBEL 2,466,054. METHOD AND APPARATUS FOR MINIMIZING PAIN CAUSEDBY DRILLING TEETH Filed Sept. 27, 1947 manna V r y INVENTOR.

5i ebel BY ATTORNEYS Patented Apr- 5, 1949 NT OFFICE nm'rnon arm mm'rusFOR ram CAUSED nrmmmmo 'ran'rn Victor B. Siebel, hiew YorL N. Y.

' Application September :1, 1941, Serial No. 176,449

My invention relates to a new and improved method and new and improvedmeans for minimizing or eliminating the pain which is caused by drillingteeth.

From actual experience, I have observed that although deaf mutes sufferthe same pain as normal persons when their teeth are extractedand inother types of dental work, such deaf mutes do not feel any pain when atooth is being drilled.

As a result of extensive observation in the dental treatment of deafmutes and from extensive experience in treatin normal patients, I havefound that in patients who can hear, the pain which results fromdrilling teeth isv due wholly or largely to the transmission of thesound waves which are produced by the drill, to the organs of hearing.Such sound waves are transmitted to the organs of hearing through thebones of the head.

According to one embodiment of my invention, I locate a microphone orother sound-pick-up means'in the mouth of the patient. This mouth 8Claims. (Cl. 128-1) which may be of equal amplitude or of any desiredphase relation.

relative amplitude, and which havethe desired These two series of majoror dominant sound waves move in opposite directions to the organs ofhearing and they produce nodes or points of zero displacement at thesound organs. Whatever the theory may be, extensive testing withpatients of normal hearing has shown that I can secure said results. Themouth microphone is preferably not too sensitive to mechanical vibranantsound waves which result from the drilling microphone is connected tothe terminals of a source of unidirectional and constant current, suchas a battery. This microphone circuit includes a variable resistor and ahand-operated switch and the primary coil of a transformer. The soundwaves which are picked up by this month microphone, thus produce avariation in said battery current, in the usual manner. The secondarycoil of said transformer is connected, preferably without amplification,to a receiver such as a telephone receiving unit. The diaphragm of thetelephone receiver thus reproduces the unamplified sound waves whichhave been picked up by the mouth microphone. This telephone receiver isconnected by two air tubes which provide two air columns of adjustablelength. to two car pieces which are held on the ears of the patient. Theends of the secondary coil are connected to a potentiometer resistor,whereby any selected secondary voltage can be supplied'to the input ofthe telephone receiver, in order to regulate the current which issupplied to the telephone receiver and hence to regulate the intensityof the external sound waves which are reproduced by the diaphragm of thetelephone re-' ceiver. The drill produces a dominant or major soundwave. By regulating said adjustable air columns,'I regulate the phase ofthe dominant or major sound wave which is transmitted through said aircolumns to the ears. I thus produce two respective series of internaland external major or dominant sound waves of the same frequency,

tion and diagrammatic drawing.

This drawing diagrammatically illustrates the circuit, when a course ofdirect current is used in the microphone circuit. 7

The mouth microphone M is made of suitable small size so that it can bekept in the mouth of the patient while the teeth are being drilled. Thismouth microphone may be of any type, such as a pressure microphone,which type includes carbon and crystal microphones. This microphone ispreferably of the button type which has carbon granules, so that theinternal electrical resistance of the microphone is regulated by thesound waves which are produced in the month by the action of the drill.One of the terminals of the microphone M is connected to a conventionalhandoperated switch 2 pivoted at l2, and which can be turned to touchthe contact 3 in order to close the circuit of battery 5. The otherterminal of the microphone is connected to one end of a resistor 4. Oneterminal of the battery 5 is connected to an adjustable connector 60.which is slidable alon the resistor 4, so that any desired resistancecan be introduced into the circuit of the mouth microphone M, inaddition to the variable resistance of the mouth microphone M. The

other terminal of the battery 5 is connected through a primary coil 6 tothe contact 3 of the blade 2. When the battery circuit is closed, theinternal sound waves which are produced in the aseaou cuit in thewell-known manner, so that a varying unidirectional current is sentthrough the primary coil '6. The primary coil 6 isinductively coupled toa secondary coil 1, whose respective ends are connected to the ends 13and H of a potentiometer'resistor a which may be of suitable highresistance, such as 25,000 ohms to'1,000,000 One terminal of aconventional telephone receiver T is connected to. the end ll of theresistor 8. The other terminal of the receiver T is connected to aslidable contact l so that any selected part of the potentiometerresistor 8 is included in the circuit of the telephone receiver T.

When the amperage oi the direct current in the 7 ,primary coil 6 isvaried by varying the intemal' resistance of mouth microphone I4 by thesound waves, a corresponding alternating signal current is induced insecondary coil 6, thus producing a corresponding alternating voltagebetween the" ends i3 and I .of the potentiometer resistor 8. Byadjusting the slide l0 between the ends I! and it of the potentiometerresistor 8, I can pick ofl any selected part of said alternatingvoltage, to be applied to the local circuit of the telephone receiver T.This telephone receiver T may be of the stand-, ard type which has adiaphragm of magnetic al-j loy and which has the coil of anelectromagnet. The ends of said coil are the terminals towhich the slidei0 and point ll are respectively connected. I The variable current whichis sent through said coil of receiver T operates the diaphragm ofreceiver T to externally reproduce the internal sound waves which areproduced in the mouth by the drill,-and which are picked up by the mouthmicrophone M. The external sound waves which are thus reproduced by thediaphragm of receiver T are transmitted through an outlet of the casingof the receiverT to a tube I! to respective tubes l6 and lid, which aretele-. scopic relative totubes i5 and lid, which are respectivelyconnected to the ear pieces 9. Since such telephone receiver iswell-known, its details are not illustrated. I n The variable resistor6a regulates the amplitude of the variations of the battery currentwhich is supplied to primary coil 6. The potentiometer 8 makes itpossible to regulate the amplitude oi the current variations which aresupplied to the input circuit of the telephone receiver unit T, andhence to regulate the external amplitude of the sound waves which areproduced by the diaphragm of the receiver unit T. The tubes I 5-46 andISa-lia interflt closely, so as to provide two respective air columns,whose respective lengths can be adjusted. Any convenetional means areprovided in order to hold the tubes l5l6 and ISa-lGa in selected i'espective adjusted positions. Said tubes are prefers ably adjusted so as toprovide respective air columns of equal length. In a practical devicewhich I have extensively tested, a range of adjustment of six inches ofsaid air columns has been found suflicient,

The velocity of sound through the bones of the head is much greater thanthrough air. By regulating the lengths of said two air columns, I canproduce external sound waves through said air columns to the organs ofhearing, which annul theinternal sound waves which are transmitted It iswell-known to use a microphone which picks up sound waves, 'to modulatea high-irequency alternating current, so that said altemating currenthas audio-frequency modulations which correspond to said picked-up soundwaves,

and to-couple said modulated alternating current with a telephonereceiver. ,Hence the invention is not limited to a system. which employsa battery current. It is alsd'fweg known to'transmit sound waves by boneconductionto'the organs or hearing, in hearing aids for deaf persons, sothat the invention is not limited to the specific method illustratedherein, in which the reprolocated in the mouth of the patient is themicrophone M and parts 01 the leads or wires which connect the terminalsof the microphone to its circuit.

I have disclosed a preferred embodiment of my, invention, but numerouschanges and omissions and additions and substitutions can be madewithout departing from its scope.

The variation in the lengths of the air columns may produce a resonanceeiiect, thus selecting one or more or the external sound waves, andsuppressing one'or more of the external sound waves;

In practical devices which I have used, the

tubes I, II, "a, lid, II are made of soft and bendable vulcanizedrubber, or hard rubber which has someflexibility. I can use othermaterials,

such asvarious plastics.

In the practical devices which I have used, the length of tube I1 isvery small, as one inch. I can also use a Y-connection, of th'e'typeused in a physicians stethoscope, in which tubes l6 and lia areconnected directly to the outlet of the casing of the receiver T, thuseliminating tube l|- and the T-connection shown in the drawing. In thecase of a Y-connection, there is a very short connector tube, like tubel1, and the outlet of the receiver T has a coupling nipple, which islocated in the interior of said connector tube by screw-threads,cementing, by a friction In api actical device which I have used, themaximum length of the air columns from the receiver-T to the ear-pieces9 is 15 inches, and the minimum length of said air-columns is 9 inches.These specific figures are illustrative, and the invention is notlimited thereto.

Ineffect, the improved device operates like a physician's stethoscope.The position of slide i0 between the ends 13 and ll of thepotentiometer, the lengths of the air columns and other factors, may beadjusted for each patient.

The invention is not limited to a method or system-in which the internalsound waves and external sound waves are of equal intensity, althoughthe regulating means can be used tomake said respective internal andexternal sound waves of equal or substantially equal intensity.

In one aspect of my invention, I use a stethoscope device whose inlet isin themouth of the patient, and whose outlets are at the ear openings,together with optional and preferred means for regulating the intensityand phase and wave form of the external sound waves which are thusdelivered to said ear openings, or for regulating said factorsindividually and in any desired combination. In the broadest aspect ofmy invention, I generally claim such stethoscope means.

As above noted, I can, by means of resonance or by selecting amicrophone or a telephone receiver, which is mainly responsive to aselected sound frequency, regulate the wave form of the sound waveswhich are delivered to the ear open ings, so as to select and deliverthe principal wave component which produces the maximum sensation ofpain.

When the apparatus is properly regulated, the patient does not hear thenoise of the drill, or said noise is at least minimized.

I claim:

1. A method of lessening the pain which is produced by drilling a toothof a patient who can hear, which consists in picking up the internalsound waves which are produced in 'the mouth of the patient by thedrill, said internal sound waves being thus picked up in the mouth ofthe patient, reproducing said internal sound waves externally of themouth to provide external sound waves, and transmitting said externalsound waves to the organs of hearing of the patient in a path whichexcludes the mouth.

2. A method according to claim 1 in which the amplitude of said externalsound waves is regulated.

3. A method according to claim 1 in which the phase and amplitude of thedominant external sound waves is regulated to substantially annul thesound of the drill.

4. Apparatus for use in lessening the pain which is produced by drillinga tooth of a patient who can hear, comprising a mouth microphone whichis sumciently small so that it can be inserted into the mouth of apatient, the terminals of said mouth microphone being connected to amicrophone circuit which includes a source of current, a telephone inputcircuit, means for coupling said microphone circuit to said telephoneinput circuit, said telephone input circuit being associated with andoperating a telephone unit, said telephone unit having an outlet whichis coupled through two air columns of adjustable length to ear pieces.

5. A system for lessening the pain which is produced by drilling thetooth of a patient who can hear, comprising a sound-wave pick-up locatedin the mouth of the patient to pick up the internal sound waves whichare produced in the mouth by the drilling action and which aretransmitted internally to the organs of hearing of the patient, andmeans operative to deliver corresponding sound waves to the organs ofhearing in a path which excludes the mouth.

6. A system according to claim 5 in which said means includeamplitude-regulating means for regulating the amplitude of saidcorresponding sound waves.

7. A system according to claim 5 in which said means havephase-regulating means to regulate the phase between said correspondingsound waves and said internal waves.

8. A system according to claim 5 in which said means includeamplitude-regulating means to regulate the amplitude of saidcorresponding sound waves and said transmitted sound waves, and alsoinclude phase-regulation means to regulate the phase relation betweensaid internal waves and said corresponding waves.

VICTOR H. SIEBEL.

No references cited.

